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Or, adopting a simpler and more explanatory arrangement, the several grand divisions of the vegetable kingdom may be exhibited as under :

I. CELLULAR-Without regular vessels, but composed of fibres which sometimes cross and interlace each other. The Conferva (green scum-like aquatic growths), the Lichens (which incrust stones and decaying trees), the Fungi (or mushroom tribe), and the Alga (or sea-weeds), belong to this division. In some of these families there are no apparent seed-organs. From their mode of growth—viz., sprout-like increase of the same organ-they are known as THALLOGENS or AMPHIGENS.

II. VASCULAR-With vessels which form organs of nutrition and reproduction. According to the arrangement of these organs, vascular plants have heen grouped into two great divisions-CRYPTOGAMIC (no visible seed-organs), and PHANEROGAMIC (apparent flowers or seed-organs). These have been further subdivided into the following classes :

1. CRYPTOGAMS-Without perfect flowers, and with no visible seed-organs. To this class belong the mosses, equisetums, ferns, and lycopodiums. It embraces many fossil forms allied to these families. From their mode of growth-viz., increase at the top or growing point only-they are known as ACROGENS.

2. PHANEROGAMIC MONOCOTYLEDONS-Flowering plants with one cotyledon or seed-lobe. This class comprises the water-lilies, lilies, aloes, rushes, grasses, canes, and palms. In allusion to their growth, by increase within, they are termed ENDOGENS. 3. PHANEROGAMIC GYMNOSPERMS-This class, as the name indicates, is furnished with flowers, but has naked seeds. It embraces the cycadea or pine-apple tribe, and the coniferæ or firs. In allusion to their naked seeds, these plants are also known as GYMNOGENS.

4. PHANEROGAMIC DICOTYLEDONS Flowering plants with two cotyledons or seed-lobes. This class embraces all forest trees and shrubs-the composita, leguminosa, umbelliferæ, cruciferæ, and other similar orders. None of the other families of plants have the true woody structure, except the coniferæ or firs, which seem to hold an intermediate place between monocotyledons and dicotyledons; but the wood of these is readily distinguished from true dicotyledonous wood. From their mode of growth-increase by external rings or layers-the dicotyledons are termed EXOGENS.

NOTE EXPLANATORY.

SPERMOCARPS (Gr. sperma, seed, and karpos, fruit).-Literally, "fruitseeded;" plants whose seeds contain an embryo, in which the rudiments of the future plant are distinguishable.

SPOROCARPS (Gr. spora, a germ, and karpos).—Literally, "produced by germs;" plants which have no seed-fruits, but which are reproduced by a development of certain germs or parts of their cellular tissues, called spores.

PHANEROGAMS (Gr. phaneros, apparent, and gamia, marriage).—Plants having apparent flowers or seed-organs.

CRYPTOGAMS (Gr. kryptos, concealed, and gamia).—Plants having no apparent seed-organs, or whose organs of reproduction are not essentially different from the other parts.

ANGIOSPERMS (Gr. angeion, a vessel, and sperma, seed).—Plants having their ovules contained in ovaries.

GYMNOSPERMS (Gr. gymnos, naked, and sperma).—Plants having their ovules in open carpels; literally, "naked or unenclosed seeds."

ANGIOSPORES (Gr. angeion and spora).-Plants having spores formed in cases which are not open till ripe.

GYMNOSPORES (Gr. gymnos and spora).-Plants having their spores superficial, and not enclosed in cases.

EXOGENS (Gr. ex, out, and gennao, I produce).-Plants whose stems increase by external layers of annual growth, as the beech and oak.

ENDOGEN (Gr. endon, within, and gennao).-Plants whose stems increase from within, by a coalescence of the footstalks of the leaves, which always encircle the growing point, as the palms and canes.

ACROGEN (Gr. akros, the summit).—Plants which increase by growth of the top or growing point, as the ferns, &c.

AMPHIGENS (Gr. amphi, around).-Plants which increase by the growth or development of their cellular tissue on all sides, as the lichens.

DICOTYLEDONS (Gr. dis, two, cotyledon, seed-lobe).—Plants whose seeds have two lobes, as the bean.

MONOCOTYLEDON (Gr. monos, one, and cotyledon).-Plants whose seeds have only one lobe, as the grasses.

THALLOGENS (Gr. thallos, a sprout).-Plants whose spores are attached to the frond or leaf, as the ferns.

AXOGAMS (Gr.)-Plants having their spores on a stem or axis, as the mosses and liverworts.

HYDROPHYTES (Gr. hydor, water, phyton, a shoot).—Water-plants, like the sea-weeds and confervæ.

AEROPHYTES (Gr. aër, the air).-Growing in the air, as the lichens, in contradistinction to the hydrophytes.

HYSTEROPHYTES (Gr. hysteros, the last).-The lowest or last of the plant-race, as the fungi or mushrooms.

Throwing these various groups into diagrammatic form, we have first the Amphigens-the fungi, lichens, and seaweeds—whose homogeneous structure and simple modes of

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growth are readily recognisable, even by the unscientific observer. Lowly alike in their aspect and functions, they cluster, as fungus-growths, over the decomposition and decay of organised tissues; mantle, as lichens, the surface of the weathering rock and the mouldering trunk; clothe, as sea-weeds, the shelves and ledges of the shallower ocean, or spread scum-like over the surface of the stagnant pool. Decay and putrescence seem to be their appointed elements; and wherever the organic cell is on the verge of dissolution into inorganic matter, there they are ready to appropriate and reconvert it once more into the circle of vitality. The pioneers of the higher orders, they elaborate a soil for their growth; cosmopolitan in habit, they are found where other plants are unknown. Such are the Amphigens now; does

the palæontologist exceed his warrant when he presumes that such they ever have been from the moment they first

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clustered over the rocks or spread their leathery lobes in

Of

the waters? Next in order come the Acrogens-the mosses, equisetums, and ferns-the lovers of the swamp and shade, and the colonists of emerging and new-formed lands. rapid and widespread growth, they have ever contributed to the consolidation of alluvial soils, and their remains mingle largely with the coals and shales of the past, as they

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do now with the peat-bogs and mud-silts of the present day. Less cosmopolitan than the amphigens, they still have

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